Ambient light based gesture detection

ABSTRACT

A gesture sensing device includes one or more sensors and a processor for processing sensed voltages output from the sensors based on ambient light and/or reflected light received by the sensors. The processor determines an ambient light level and/or a distance between the target and the sensors such that, if the ambient light level exceeds an ambient light threshold and/or the distance is less than a distance threshold, the processor determines the motion of a target relative to the sensors based on the ambient light instead of the reflected light.

FIELD OF THE INVENTION

This invention relates to gesture detection. More specifically, thisinvention relates to a device that senses and determines physicalgestures.

BACKGROUND OF THE INVENTION

A gesture sensor is a human interface device that enables the detectionof physical movement without the user actually touching the devicewithin which the gesture sensor resides. The detected movements can besubsequently used as input commands to the device. In some applications,the device is programed to recognize distinct non-contact hand motions,such as left to right, right to left, up to down, down to up, diagonallyup to left, diagonally up to right, in to out, and out to in handmotions. Gesture sensors have found popular use in handheld devices,such as tablet computing devices and smartphones, and other portabledevices, such as laptops. Gesture sensors are also being implemented invideo game consoles that detect the motion of a video game player.

FIG. 1 illustrates a conventional gesture sensing system 100. As shownin FIG. 1, the system 100 includes an illumination source 102 foroutputting light 106 and a light sensor 104 for receiving light. Inoperation, the illumination source 102 is turned on and off, or flashed,in succession in order for the sensor 104 to obtain spatial informationabout an object 99 proximate the light sensor 104. Specifically, thelight sensor 104 is able to receive a portion of the light 106 from theillumination source 102 that has reflected off of the object 99 and backto the light sensor 104. Based on this received reflected light 108, themovement or gesture of the object 99 is able to be determined. FIG. 2illustrates a signal diagram 200 corresponding to the gesture sensorsystem 100 shown in FIG. 1. Specifically, as shown in FIG. 2, as theillumination source signal 202 turns on from time t0 to t1 and time t2to t3 (e.g. the illumination source 102 flashes) the reflected light 108received by the light sensor 104 causes the light sensor signal 204 toincrease above the measured ambient light level 210 wherein the increasecorresponds to the spatial characteristics of the object 99. As aresult, movement or gestures of the object 99 are able to be determinedbased on the measured increases over time.

However, a disadvantage of these conventional systems 100 is the amountof noise on the sensor 104 of the system caused by the ambient light110. In particular, as the ambient light level 210 increases the minimumdetectable signal increases thereby reducing the resolution andeffectiveness of the system 100. As a result, many of these systems areforced to employ costly noise cancellation elements in order to cancelout the noise caused by the ambient light. With ever decreasing devicesize, additional components are undesirable.

SUMMARY OF THE INVENTION

Embodiments are disclosed of a gesture sensing device comprise one ormore sensors and a processor for processing sensed voltages output fromthe sensors based on ambient light and/or reflected light received bythe sensors. The processor determines an ambient light level and/or adistance between the target and the sensors such that, if the ambientlight level exceeds an ambient light threshold and/or the distance isless than a distance threshold, the processor determines the motion of atarget relative to the sensors based on the ambient light instead of thereflected light.

A first aspect of the present application is directed to a device fordetecting a gesture by a target. The device comprises one or more lightsensors that each output a sensor signal corresponding to ambient lightsensed by the sensors and a processor coupled with the light sensors,wherein the processor determines a motion of the target based on theambient light received by the sensors as the target moves proximate thelight sensors. In some embodiments, the processor is not coupled with asource of the ambient light. In some embodiments, the device furthercomprises a detector coupled with the processor, wherein the detectordetermines an ambient light value based on the ambient light. In someembodiments, the processor only determines the motion of the targetbased on the ambient light if the ambient light value exceeds an ambientlight threshold value. In some embodiments, the detector is one or moreof the light sensors, and the detector outputs one of the sensorsignals. In some embodiments, the processor only determines the motionof the target based on the ambient light if a distance valuecorresponding to the distance from the sensors to the target is within atarget distance threshold value. In some embodiments, the processordetermines if the target is present based on the ambient light if thedistance value is not within the target distance threshold value. Insome embodiments, the device further comprises a light source coupledwith the processor that outputs source light, wherein the distance valueis determined by the processor based on source light reflected off thetarget and received by the sensors. In some embodiments, the processorcauses the light source to only output light for a period sufficient todetermine the distance value. In some embodiments, if the ambient lightvalue does not exceed the ambient light threshold value, the processordetermines the motion of the target based on the source light reflectedoff the target and received by the sensors. The processor determines themotion of the target periodically, continuously or selectively. In someembodiments, the processor determines the motion of the target based onthe ambient light by monitoring sudden decreases in the sensor signal.In some embodiments, the processor determines the motion of the targetbased on the source light reflected off the target by monitoring suddenincreases in the sensor signal.

A second aspect of the present application is directed to a method ofdetecting a gesture by a target. The method comprises receiving ambientlight with one or more light sensors and outputting a sensor signalcorresponding to ambient light sensed by the sensors and determining amotion of the target based on the ambient light received by the sensorsas the target moves proximate the light sensors. In some embodiments,the processor is not coupled with a source of the ambient light. In someembodiments, the method further comprises determining an ambient lightvalue based on the ambient light with a detector. In some embodiments,the processor only determines the motion of the target based on theambient light if the ambient light value exceeds an ambient lightthreshold value. In some embodiments, the detector is one or more of thelight sensors, and the detector outputs one of the sensor signals. Insome embodiments, the processor determines the motion of the targetbased on the ambient light only if a distance value corresponding to thedistance from the sensors to the target is within a target distancethreshold value. In some embodiments, the method further comprisesdetermining if the target is present based on the ambient light if thedistance value is not within the target distance threshold value. Insome embodiments, the method further comprises outputting source lightwith a light source, wherein the distance value is determined by theprocessor based on source light reflected off the target and received bythe sensors. In some embodiments, the processor causes the light sourceto only output light for a period sufficient to determine the distancevalue. In some embodiments, the method further comprises determining themotion of the target based on the source light reflected off the targetand received by the sensors if the ambient light value does not exceedthe ambient light threshold value. The processor determines the motionof the target periodically, continuously or selectively. In someembodiments, the processor determines the motion of the target based onthe ambient light by monitoring sudden decreases in the sensor signal.In some embodiments, the processor determines the motion of the targetbased on the source light reflected off the target by monitoring suddenincreases in the sensor signal.

Another aspect of the present application is directed to a device fordetecting a gesture by a target. The device comprises a first lightsource for producing a first light, one or more sensors for sensing thefirst light and a second light and a processor coupled with the one ormore sensors, wherein the processor determines the motion of the targetbased on the second light received by the sensors if ambient lightreceived by the sensors is greater than an ambient light threshold valueand otherwise determines the motion of the target based on the firstlight received by the sensors. In some embodiments, the processor is notcoupled with the source of the second light. In some embodiments, theprocessor determines the motion of the target based on the second lightonly if the ambient light received by the sensors is greater than theambient light threshold value and the target is within a thresholddistance from the sensors. In some embodiments, the processor determinesif the target is present if the ambient light received by the sensors isgreater than the ambient light threshold value, but the target is notwithin the threshold distance from the sensors. In some embodiments, thefirst light reflects off of the target before being sensed by thesensors and the second light does not reflect off the target beforebeing sensed by the sensors. In some embodiments, the second light is aportion of the ambient light. In some embodiments, the device furthercomprises a detector coupled with the processor, wherein the detectordetermines the ambient light value based on the ambient light. In someembodiments, the detector is one or more of the light sensors. In someembodiments, the distance between the sensors and the target isdetermined by the processor based on the first light reflected off thetarget and received by the sensors. In some embodiments, the processorcauses the first light source to only output the first light for aperiod sufficient to determine the distance between the target and thesensors. The processor determines the motion of the target periodically,continuously or selectively. In some embodiments, the processordetermines the motion of the target based on the second light bymonitoring sudden decreases in a sensor signal, wherein the sensorsignal is output by the sensors based on the received first light andsecond light. In some embodiments, the processor determines the motionof the target based on the first light reflected off the target bymonitoring sudden increases in the sensor signal.

Yet another aspect of the present application is directed to a method ofdetecting a gesture by a target. The method comprises sensing a firstlight produced by a first light source and a second light with one ormore sensors and determining the motion of the target with a processorbased on the second light received by the sensors if ambient lightreceived by the sensors is greater than an ambient light threshold valueand otherwise determining the motion of the target based on the firstlight received by the sensors. In some embodiments, the processor is notcoupled with the source of the second light. In some embodiments, themethod further comprises determining the motion of the target with theprocessor based on the second light if the ambient light received by thesensors is greater than the ambient light threshold value and the targetis within a threshold distance from the sensors. In some embodiments,the method further comprises determining if the target is present withthe processor if the ambient light received by the sensors is greaterthan the ambient light threshold value, but the target is not within thethreshold distance from the sensors. In some embodiments, the firstlight reflects off of the target before being sensed by the sensors andthe second light does not reflect off the target before being sensed bythe sensors. In some embodiments, the second light is a portion of theambient light. In some embodiments, the method further comprisesdetermining the ambient light value with a detector based on the ambientlight. In some embodiments, the detector is one or more of the lightsensors. In some embodiments, the method further comprises determiningthe distance between the sensors and the target with the processor basedon the first light reflected off the target and received by the sensors.In some embodiments, the method further comprises only outputting thefirst light with the first light source for a period sufficient todetermine the distance between the target and the sensors. The processordetermines the motion of the target periodically, continuously orselectively. In some embodiments, the processor determines the motion ofthe target based on the second light by monitoring sudden decreases in asensor signal, wherein the sensor signal is output by the sensors basedon the received first light and second light. In some embodiments, theprocessor determines the motion of the target based on the first lightreflected off the target by monitoring sudden increases in the sensorsignal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a conventional gesture sensing system.

FIG. 2 illustrates a signal diagram corresponding to the conventionalgesture sensor system shown in FIG. 1.

FIG. 3 illustrates a conceptual diagram of a gesture sensing systemaccording to some embodiments.

FIG. 4 illustrates a signal diagram corresponding to the ambient lightmode of the gesture sensing system shown in FIG. 3 according to someembodiments.

FIG. 5 illustrates a flow chart of a method of using a gesture sensingsystem according to some embodiments.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present application are directed to a gesture sensingdevice for detecting gestures. Those of ordinary skill in the art willrealize that the following detailed description of the device isillustrative only and is not intended to be in any way limiting. Otherembodiments of the device will readily suggest themselves to suchskilled persons having the benefit of this disclosure.

Reference will now be made in detail to implementations of the device asillustrated in the accompanying drawings. The same reference indicatorswill be used throughout the drawings and the following detaileddescription to refer to the same or like parts. In the interest ofclarity, not all of the routine features of the implementationsdescribed herein are shown and described. For example, the devicedescribed below is able to comprise one or more additional componentsuch as memory as are well known in the art, but have been omitted herefor the sake of brevity. It will, of course, be appreciated that in thedevelopment of any such actual implementation, numerousimplementation-specific decisions will likely be made in order toachieve the developer's specific goals, such as compliance withapplication and business related constraints, and that these specificgoals can vary from one implementation to another and from one developerto another. Moreover, it will be appreciated that such a developmenteffort might be complex and time-consuming, but would nevertheless be aroutine undertaking of engineering for those of ordinary skill in theart having the benefit of this disclosure.

Embodiments of a gesture sensing device and method are described herein.The gesture sensing device comprises one or more sensors and a processorfor processing sensed voltages output from the sensors based on ambientlight and/or reflected light received by the sensors. In operation, theprocessor determines an ambient light level and/or a distance betweenthe target and the sensors such that, if the ambient light level exceedsan ambient light threshold and/or the distance is less than a distancethreshold, the processor determines the motion of a target relative tothe sensors based on the ambient light instead of the reflected light.Thus, the gesture sensing device and method provides the advantage ofmaking the ambient light the signal instead of noise in areas with highambient light levels. As a result, the device and method provideaccurate and lower cost operation in areas of high ambient light levelsbecause it does not need costly ambient light and/or other noisecancellation features. Further, the gesture sensing device and methodprovide the advantage of increased power saving due to its ability touse existing ambient light instead of powering a light source. Finally,the gesture sensing device and method provides the advantage of enablingswitching between two or more gesture sensing modes and a presencesensing based on the levels of ambient light and/or distance of thetarget thereby tailoring the sensing mode to the environment. As usedherein, a gesture of the target is able to comprise velocity,acceleration, rotation and/or other spatial characteristics of thetarget, and ambient light is able to comprise light whose source is notcontrolled or powered by the device and/or light controlled or poweredby the device but not reflected off the target.

FIG. 3 illustrates a conceptual diagram of a gesture sensing system 300according to some embodiments. As shown in FIG. 3, the gesture sensingsystem 300 comprises a target 99 and a gesture sensing device 314. Insome embodiments, the target 99 is a finger or hand Alternatively, thetarget 99 is able to be any tangible object as are well known in theart. In some embodiments, the gesture sensing device 314 is a mobilecomputing device including but not limited to a mobile phone, tabletcomputer, PDA, gaming device, gaming controller, laptop computer, ordesktop computer. Alternatively, the gesture sensing device 314 is ableto be one or more other electronic devices as are well known in the art.The gesture sensing device 314 comprises one or more light sources 302for outputting light 306, one or more light sensors 304 for receivinglight, an ambient light detector 316 and at least one processor 312coupled with the ambient light detector 316, the light sources 302 andlight sensors 304. Alternatively, one or more of the above componentsare able to be separate from the device 314. In some embodiments, theprocessor 312 is electrically coupled with the ambient light detector316, the light sources 302 and/or the light sensors 304. Alternatively,the processor 312 is able to be wirelessly or otherwise coupled with theambient light detector 316, the light sources 302 and/or light sensors304 such that the processor 312 is able to receive output signals fromthe ambient light detector 316 and the light sensors 304, and transmitcontrol signals to the light sources 302. In some embodiments, the lightsources 302 comprise light emitting diodes (LEDs). Alternatively, one ormore of the light sources 302 are able to comprise other types of lightemitting devices or elements as are well known in the art. In someembodiments, the light sensors 304 comprise photo detectors.Alternatively, one or more of the light sensors 304 are able to compriseother types of light detecting devices or elements as are well known inthe art. In some embodiments, the ambient light detector 316 is one ormore of the light sensors 304. Alternatively, the ambient light detector316 is distinct from the light sensors 304.

In operation, the ambient light detector 316 detects ambient light 310within the system 300 and outputs an ambient light signal or value basedon the received ambient light 310 to the processor 312. The processor312 compares the received ambient light signal or value to a preselectedambient light threshold value stored in processor memory or other memory(not shown) on the device 314. If the ambient light value/signal is notgreater than the ambient light threshold value, the processor 312switches to or continues determining the gestures of the target 99 basedon the source light 306, 308. Specifically, if the value/signal is notgreater, the gesture information is obtained by flashing or turning thelight source 302 on and off in succession with the processor 312. Inparticular, the light sensors 304 are able to receive a reflectedportion 308 of the source light 306 from the flashed light source 302that has reflected off of the target 99 and back to the light sensors304. Based on this received reflected light 308, the gesture of thetarget 99 is able to be determined by monitoring sudden increases or“bumps” in the sensed light 308 over time. These “bumps” correspond tochanges in the amount of light 308 reflected off of the target 99because of movement or gestures of the target 99. As a result, the“bumps” enable the processor 312 to determine the gestures of the target99. In this “source light mode,” the source light 306, 308 is consideredthe signal and the ambient light 310 is considered noise such that asambient light levels increase the signal to noise ratio becomes worse.

However, if the ambient light value/signal is greater than the ambientlight threshold value, the processor 312 switches to or continuesdetermining either the gestures or presence of the target 99 based onthe ambient light 310. Specifically, if the ambient light value/signalis greater, the gesture or presence of the target 99 is determined byturning off the light source 302 with the processor 312 such that onlythe ambient light 310 (not reflected source light 308) is received bythe sensors 304. In particular, the light sensors 304 are able toreceive a portion of the ambient light 310 that has not been blocked oroccluded by the target 99. Based on this received ambient light 310, thepresence or gesture of the target 99 is able to be determined bymonitoring sudden decreases or “dips” 414 (see FIG. 4) in the sensedambient light 310 over time. These “dips” 414 correspond to changes inthe amount of light occluded by the target 99 because of the presence orgestures of the target 99. As a result, these “dips” 414 enable theprocessor 312 to determine the presence or gestures of the target 99. Inthis “ambient light mode,” the ambient light 310 itself is consideredthe signal such that as the ambient light levels increase the signal tonoise ratio improves. Thus, the device 314 is able to provide theadvantage of efficient operation low ambient light areas as well as inhigh ambient light areas with improved signal to noise ratios and noneed for ambient light noise cancellation components.

In order to distinguish between presence determination and gesturedetermination, during “ambient light mode,” the device 314 performs atarget proximity test. Specifically, if the target 99 is discovered tobe proximate the sensors 304, the ambient light 310 is able to be usedto determine the gestures of the target 99. Alternatively, if the target99 is discovered to be remote from the sensors 304, the ambient light310 is able to be used to determine the presence of the target 99. Insome embodiments, the target proximity test is performed after thecomparison of the ambient light threshold value, but before monitoringthe signal or signals output by the sensors 304 for decreases or “dips”414. Alternatively, the target proximity test is able to be performed atany time during operation. During the proximity test, the processor 312turns on the light source 302 for a proximity period 406 (see FIG. 4) inorder to determine if the target 99 is proximate the sensors 304. Thisprocess is similar to the gesture detection using the reflected light306 in “source light mode” described above, except that the proximityperiod 406 is only long enough for the processor 312 to determine thatthe reflected light 308 received by the sensors 304 indicates theproximity or lack of proximity of the target 99. Alternatively, theproximity period 406 is able to be greater than the time required todetermine proximity of the target 99 using the reflected light 308.

In some embodiments, this proximity determination/test is performed bythe processor 312 comparing the increase or “bump” 408 (see FIG. 4) inthe sensor signal or signals during the proximity period 406 to aproximity threshold value. Alternatively, the proximity determination isperformed by comparing the maximum or average value of the sensor signalor signals during the proximity period 406 to the proximity thresholdvalue. In either case, if the change or value of the sensor signal isgreater than the proximity threshold value, the target 99 is determinedto be proximate the sensors 304, and if not the target 99 is determinedto be remote from the sensors 304. In some embodiments, the proximitythreshold value is dynamic and determined based on the received ambientlight 310 such that the proximity threshold is adjusted to always be apredefined delta value greater than the current ambient light 310 value.In such embodiments, the delta value is able to be selected based on theeffects of the distance of the target 99 from the sensors 304 on thesensor signal or signals such that the delta value corresponds to adesired distance between the target 99 and the sensors 304.Alternatively, the proximity threshold value is able to be a predefinedstatic value. Thus, the gesture sensing device 314 is able to switchbetween ambient light presence sensing and ambient light gesture sensingbased on the proximity of the target 99. This enables the gesturesensing device 314 to ensure the accuracy of the gesture sensing byminimizing the possibility of shadowing effects causing a false gesturedetection when the target 99 is remote from the sensors 304. In someembodiments, other forms of target 99 proximity detection are able to beused in place of or in cooperation with the light source 302 as are wellknown in the art. Alternatively, use of the light source 302 forproximity detection and/or other proximity detection is able to beomitted such that the device 314 selectively operates in presencedetection mode or gesture detection mode.

It is understood that each of the operations discussed above are able tobe performed by the device 314 continuously, periodically, and/or upondemand. For example, the processor 312 is able to continuously,periodically and/or upon request from a user check the ambient lightlevels received by the ambient light detector 316 to determine if thedevice 314 should switch between using the ambient light 130 or thesource light 306, 308 to determine target 99 gestures. Additionally, itis understood, that although the operation of the gesture sensing device314 is described beginning with the detection of the ambient light 310,the operation is able to begin at other points as described above.

FIG. 4 illustrates a signal diagram 400 corresponding to the ambientlight mode of the gesture sensing system 300 shown in FIG. 3 accordingto some embodiments. Specifically, as shown in FIG. 4, during theproximity period 406, the light source signal 402 goes from “low” to“high” as the light source 302 is turned on or flashed by the processor312. As a result, if the target 99 is proximate the sensors 304 as shownin FIG. 3, the sensor signal 304 will exhibit a sudden increase or“bump” 408 over the ambient light level 410 due to the reflected light308 received from the light source 302 as described above. Accordingly,once the proximity period 406 has ended and the light source 302 hasbeen turned off, the processor 312 is able to monitor the sensor signal404 for sudden decreases or “dips” 414 during a gesture or presencesensing period 412 and use that data to calculate the presence orgestures of the target 99. In particular, the device 314 is able todetermine the presence of the target 99 if the target 99 was determinedto not be proximate the sensors 304 and is able to determine thegestures of the target 99 if the target 99 was proximate. In someembodiments, the presence or gesture sensing period 412 lasts from theend of one proximity period 406 to the beginning of the next proximityperiod 406.

Alternatively, the presence or gesture sensing period 412 is able to beless or more than the time between proximity periods 406. These ambientlight mode proximity detection processes and monitoring processes areable to be repeated over time in order to monitor the “dips” 414 causedby targets and enable the processor 312 to determine the presence and/orgestures of the target 99.

FIG. 5 illustrates a flow chart of a method of using a gesture sensingsystem 300 of FIG. 3 according to some embodiments. At the step 502, theambient light detector 316 and light sensors 304 receive ambient light310 and output a detector signal to the processor 312 corresponding toan ambient light value sensed by the detector 316. In some embodiments,the detector 316 is one or more of the light sensors 304. At the step504, the processor 312 determines if the ambient light value exceeds anambient light threshold value. At the step 506, if the ambient lightvalue does not exceed the ambient light threshold value, the lightsource 302 outputs source light 306 and the processor 312 determines thegesture of the target 99 based on the source light 308 reflected off thetarget 99 to the sensors 304. In some embodiments, the processor 312determines the gestures of the target 99 based on the source light 308reflected off the target 99 by monitoring sudden increases in the sensorsignal 404. At the step 508, if the ambient light value does exceed theambient light threshold value, the light source 302 outputs source light306 and the processor 312 determines if the target 99 is proximate thelight sensors 304 based on the source light 308 reflected off the target99 to the sensors 304. In some embodiments, the processor 312 determineswhether the target 99 is proximate the sensors 304 by comparing adistance value corresponding to the distance between the sensors 304 andthe target 99 with a target distance threshold value, wherein if thedistance value is within the threshold value the target 99 is determinedto be proximate. In some embodiments, the processor 312 determines thedistance value by outputting source light 306 with the light source 302,wherein the distance value is based on the source light 308 reflectedoff the target 99 to the sensors 304. In some embodiments, the processor312 causes the light source 302 to only output source light 306 for aproximity period 406 sufficient to determine the distance value.Alternatively, the step 508 is able to be omitted. At the step 510, ifthe target 99 is proximate the light sensors 304, the processor 312determines the gesture of the target 99 based on the ambient light 310received by the sensors 304. In some embodiments, the processor 312determines the gesture of the target 99 based on the ambient light 310by monitoring sudden decreases 414 in the sensor signal 404. At the step512, if the target 99 is not proximate the light sensors 304, theprocessor 312 determines whether the target 99 is present based on theambient light 310 received by the sensors 304. In some embodiments, theprocessor 312 determines the gestures and/or presence of the target 99periodically, continuously or selectively.

The device and method of ambient light based gesture detection describedherein has numerous advantages. Specifically, the device and method isable to operate efficiently at both high and low ambient light levelswithout the increased cost of ambient light cancellation components orsignal amplifying components such as lenses. Indeed, unlike othermethods and devices, the signal to noise ratio of the device and methodis actually improved with increased ambient light levels. Further, thedevice and method are able to use less power by minimizing the need topower a light source for providing reflected light to detect thegestures. Moreover, the device and method provides the advantage ofusing proximity detection to switch between presence detection andgesture detection thereby minimizing the possibility of false gesturereadings due to shadowing effect. Accordingly, it is clear that theambient light based gesture device and method described herein has manybenefits.

The present application has been described in terms of specificembodiments incorporating details to facilitate the understanding of theprinciples of construction and operation of the gesture sensing deviceand method for detecting gestures. Many of the components shown anddescribed in the various figures can be interchanged to achieve theresults necessary, and this description should be read to encompass suchinterchange as well. As such, references herein to specific embodimentsand details thereof are not intended to limit the scope of the claimsappended hereto. It will be apparent to those skilled in the art thatmodifications can be made to the embodiments chosen for illustrationwithout departing from the spirit and scope of the application.

What is claimed is:
 1. A device for detecting a gesture by a targetcomprising: a. one or more light sensors that each output a sensorsignal corresponding to ambient light sensed by the sensors; and b. aprocessor coupled with the light sensors, wherein the processordetermines a motion of the target based on the ambient light received bythe sensors as the target moves proximate the light sensors.
 2. Thedevice of claim 1 wherein the processor is not coupled with a source ofthe ambient light.
 3. The device of claim 1 further comprising adetector coupled with the processor, wherein the detector determines anambient light value based on the ambient light.
 4. The device of claim 3wherein the processor only determines the motion of the target based onthe ambient light if the ambient light value exceeds an ambient lightthreshold value.
 5. The device of claim 4 wherein the detector is one ormore of the light sensors, and the detector outputs one of the sensorsignals.
 6. The device of claim 4 wherein the processor only determinesthe motion of the target based on the ambient light if a distance valuecorresponding to the distance from the sensors to the target is within atarget distance threshold value.
 7. The device of claim 6 wherein theprocessor determines if the target is present based on the ambient lightif the distance value is not within the target distance threshold value.8. The device of claim 6 further comprising a light source coupled withthe processor that outputs source light, wherein the distance value isdetermined by the processor based on source light reflected off thetarget and received by the sensors.
 9. The device of claim 8 wherein theprocessor causes the light source to only output light for a periodsufficient to determine the distance value.
 10. The device of claim 8wherein if the ambient light value does not exceed the ambient lightthreshold value, the processor determines the motion of the target basedon the source light reflected off the target and received by thesensors.
 11. The device of claim 10 wherein the processor determines themotion of the target periodically, continuously or selectively.
 12. Thedevice of claim 11 wherein the processor determines the motion of thetarget based on the ambient light by monitoring sudden decreases in thesensor signal.
 13. The device of claim 12 wherein the processordetermines the motion of the target based on the source light reflectedoff the target by monitoring sudden increases in the sensor signal. 14.A method of detecting a gesture by a target comprising: a. receivingambient light with one or more light sensors and outputting a sensorsignal corresponding to ambient light sensed by the sensors; and b.determining a motion of the target based on the ambient light receivedby the sensors as the target moves proximate the light sensors.
 15. Themethod of claim 14 wherein the processor is not coupled with a source ofthe ambient light.
 16. The method of claim 14 further comprisingdetermining an ambient light value based on the ambient light with adetector.
 17. The method of claim 16 wherein the processor onlydetermines the motion of the target based on the ambient light if theambient light value exceeds an ambient light threshold value.
 18. Themethod of claim 17 wherein the detector is one or more of the lightsensors, and the detector outputs one of the sensor signals.
 19. Themethod of claim 17 wherein the processor determines the motion of thetarget based on the ambient light only if a distance value correspondingto the distance from the sensors to the target is within a targetdistance threshold value.
 20. The method of claim 19 further comprisingdetermining if the target is present based on the ambient light if thedistance value is not within the target distance threshold value. 21.The method of claim 19 further comprising outputting source light with alight source, wherein the distance value is determined by the processorbased on source light reflected off the target and received by thesensors.
 22. The method of claim 21 wherein the processor causes thelight source to only output light for a period sufficient to determinethe distance value.
 23. The method of claim 21 further comprisingdetermining the motion of the target based on the source light reflectedoff the target and received by the sensors if the ambient light valuedoes not exceed the ambient light threshold value.
 24. The method ofclaim 23 wherein the processor determines the motion of the targetperiodically, continuously or selectively.
 25. The method of claim 24wherein the processor determines the motion of the target based on theambient light by monitoring sudden decreases in the sensor signal. 26.The method of claim 25 wherein the processor determines the motion ofthe target based on the source light reflected off the target bymonitoring sudden increases in the sensor signal.
 27. A device fordetecting a gesture by a target comprising: a. a first light source forproducing a first light; b. An array of sensors for sensing the firstlight and a second light; and c. a processor coupled with the one ormore sensors, wherein the processor determines the motion of the targetbased on the second light received by the sensors if ambient lightreceived by the sensors is greater than an ambient light threshold valueand otherwise determines the motion of the target based on the firstlight received by the sensors.
 28. The device of claim 27 wherein theprocessor is not coupled with the source of the second light.
 29. Thedevice of claim 28 wherein the processor determines the motion of thetarget based on the second light only if the ambient light received bythe sensors is greater than the ambient light threshold value and thetarget is within a threshold distance from the sensors.
 30. The deviceof claim 29 wherein the processor determines if the target is present ifthe ambient light received by the sensors is greater than the ambientlight threshold value, but the target is not within the thresholddistance from the sensors.
 31. The device of claim 30 wherein the firstlight reflects off of the target before being sensed by the sensors andthe second light does not reflect off the target before being sensed bythe sensors.
 32. The device of claim 31 wherein the second light is aportion of the ambient light.
 33. The device of claim 32 furthercomprising a detector coupled with the processor, wherein the detectordetermines the ambient light value based on the ambient light.
 34. Thedevice of claim 33 wherein the detector is one or more of the lightsensors.
 35. The device of claim 33 wherein the distance between thesensors and the target is determined by the processor based on the firstlight reflected off the target and received by the sensors.
 36. Thedevice of claim 35 wherein the processor causes the first light sourceto only output the first light for a period sufficient to determine thedistance between the target and the sensors.
 37. The device of claim 36wherein the processor determines the motion of the target periodically,continuously or selectively.
 38. The device of claim 37 wherein theprocessor determines the motion of the target based on the second lightby monitoring sudden decreases in a sensor signal, wherein the sensorsignal is output by the sensors based on the received first light andsecond light.
 39. The device of claim 38 wherein the processordetermines the motion of the target based on the first light reflectedoff the target by monitoring sudden increases in the sensor signal. 40.A method of detecting a gesture by a target comprising: a. sensing afirst light produced by a first light source and a second light with oneor more sensors; and b. determining the motion of the target with aprocessor based on the second light received by the sensors if ambientlight received by the sensors is greater than an ambient light thresholdvalue and otherwise determining the motion of the target based on thefirst light received by the sensors.
 41. The method of claim 40 whereinthe processor is not coupled with the source of the second light. 42.The method of claim 41 further comprising determining the motion of thetarget with the processor based on the second light if the ambient lightreceived by the sensors is greater than the ambient light thresholdvalue and the target is within a threshold distance from the sensors.43. The method of claim 42 further comprising determining if the targetis present with the processor if the ambient light received by thesensors is greater than the ambient light threshold value, but thetarget is not within the threshold distance from the sensors.
 44. Themethod of claim 43 wherein the first light reflects off of the targetbefore being sensed by the sensors and the second light does not reflectoff the target before being sensed by the sensors.
 45. The method ofclaim 44 wherein the second light is a portion of the ambient light. 46.The method of claim 45 further comprising determining the ambient lightvalue with a detector based on the ambient light.
 47. The method ofclaim 46 wherein the detector is one or more of the light sensors. 48.The method of claim 45 further comprising determining the distancebetween the sensors and the target with the processor based on the firstlight reflected off the target and received by the sensors.
 49. Themethod of claim 48 further comprising only outputting the first lightwith the first light source for a period sufficient to determine thedistance between the target and the sensors.
 50. The method of claim 49wherein the processor determines the motion of the target periodically,continuously or selectively.
 51. The method of claim 50 wherein theprocessor determines the motion of the target based on the second lightby monitoring sudden decreases in a sensor signal, wherein the sensorsignal is output by the sensors based on the received first light andsecond light.
 52. The method of claim 51 wherein the processordetermines the motion of the target based on the first light reflectedoff the target by monitoring sudden increases in the sensor signal.